#160: Write unit tests for ScriptDetector

[aaronhktan]

Description

This commit adds unit tests for the ScriptDetector class, and also adds code to ChineseUtils to check for invalid tones in Jyutping/Pinyin.

Part of a series of commits for #160.

Type of change

• [x] Bug fix (non-breaking change which fixes an issue)

How Has This Been Tested?

Tested on all three platforms.

********* Start testing of TestScriptDetector *********
Config: Using QtTest library 5.15.12, Qt 5.15.12 (x86_64-little_endian-lp64 shared (dynamic) release build; by GCC 12.3.0), pop 22.04
PASS   : TestScriptDetector::initTestCase()
PASS   : TestScriptDetector::simplifiedChinese()
PASS   : TestScriptDetector::noSimplifiedChinese()
PASS   : TestScriptDetector::traditionalChinese()
PASS   : TestScriptDetector::noTraditionalChinese()
PASS   : TestScriptDetector::chinese()
PASS   : TestScriptDetector::noChinese()
PASS   : TestScriptDetector::validJyutping()
PASS   : TestScriptDetector::noValidJyutping()
PASS   : TestScriptDetector::validPinyin()
PASS   : TestScriptDetector::noValidPinyin()
PASS   : TestScriptDetector::cleanupTestCase()
Totals: 12 passed, 0 failed, 0 skipped, 0 blacklisted, 11ms
********* Finished testing of TestScriptDetector *********

Checklist:

• [x] My code follows the style guidelines of this project (black for Python code, .clang-format in the src/jyut-dict directory for C++)
• [x] I have performed a self-review of my own code
• [x] I have commented my code, particularly in hard-to-understand areas
• [x] I have translated my user-facing strings to all currently-supported languages
• [x] I have made corresponding changes to the documentation